Advanced High-Entropy Halide Solid Electrolytes Enabling High-Voltage, Long-Cycling All-Solid-State Batteries
Ye Yu, Zhi Gu, Jiazhong Geng, Kangdi Niu, Pengcheng Yu, Yu Zhou, Junhao Lin, H. J. Woo, Yizhou Zhu, Jiayu Wan
Abstract
Stable solid electrolytes are essential for advancing the safety and energy density of lithium batteries, especially in high-voltage applications. In this study, we designed an innovative high-entropy chloride solid electrolyte (HE-5, Li 2.2 In 0.2 Sc 0.2 Zr 0.2 Hf 0.2 Ta 0.2 Cl 6 ), using multielement doping to optimize both ionic conductivity and high-voltage stability. The high-entropy disordered lattice structure facilitates lithium-ion mobility, achieving an ionic conductivity of 4.69 mS cm –1 at 30 °C and an activation energy of 0.300 eV. Integration of HE-5 into all-solid-state batteries (ASSBs) with NCM83 cathodes and a Li–In anode enables outstanding electrochemical performance, sustaining 70% capacity retention over 1600 cycles at a 4 C rate. Moreover, the high configurational entropy stabilizes the electrolyte’s structure at elevated voltages, enabling stable operation at 5.0 V without significant degradation. Our work presents the dual advantages of high-entropy engineering in boosting high ionic conductivity and voltage stability, providing a broad roadmap for next-generation energy-dense ASSBs.